Improvement in dyeing yarns and fabrics in aniline-black



UNITE WILLIAM J. s. GRAWITZ, or PARIS, FRANCE.

IMPROVEMENT IN DYEINGVARNS AND FABRICS IN ANiLlNE-BLACK.

Specification forming part of Letters Patent No. it; 3,1158, dated July17, 1877 application filed March 13, 1877; patented in England, October21, 1874, for fourteen years.

To all whom it may concern:

Be it known that 1, WILLIAM J ULES SAM- U'EL GRAWITZ, of Paris, France,chemist, have invented Improvements in the Production of.

Aniline Blacks and Grays, and in the application of the same for dyeingtextile materials; and I do hereby declare that the following is a full,clear, and exact description of the same.

This invention relates to certain chemical reactions, having for objectthe production from aniline of a series of black colors, or shadesbordering on black, and also to the processes employed in applying thesame for dyeing textile materials.

The novel chemical reactions of my inven tion consist in the concurrentaction on aniline-oil or on its salts, of certain metallic salts andsoluble chromates or bichromates or chlorates, without the necessity ofexposure to air.

The action of the metallic salts may either precede or i follow that ofthe chromates or bichromates, and both may be performed with or withoutthe aid of heat.

I will proceed to describe the three principal modifications of myinvention in the dyeing of textile materials.

The first modification consists in the formation of a complex base,containing both aniline and a metal, this base being obtained byprecipitating certain metallic salts by means of aniline-oil. Thesecomplex bases redissolve in acids.

Thesecond modification consists in forming a bath containing theelements of a double salt of aniline and of metal. For example, I placetogether in the bath equal equivalents of perchloride of iron andhydrochlorate of aniline.

The third modification consists in forming a bath containing theelements of an aniline salt combined with the metal-that isto say, saltsof aniline with a metallic acid. This latter modification includes theformation, by double decomposition in the baths, of ferro and ferricyanides of aniline, of chromates and bichromates, manganates andpermanganates, tungstates, vanadates, and bivanadates of aniline.

These complex bases, these double salts of aniline and of metal, thesesalts of aniline with a metallic acid, have all the property of enablingthe aniline to gradually oxidize with the greatest facility, produceblack, or shades bordering on black, according to the degree ofoxidation.

The application to dyeing textile materials of the above series ofreactions and of processes may be efl'ectedin one, two, or three baths.

The following is the method of dyeing with three baths. The complexbases above referred to are precipitated on the materials to be dyed, byfirst impregnating with aniline then with the metallic salt, the textilematters being carefully drained between each bath. The black is thendeveloped by introducing the textiles into a bath of soluble chromates,bichromates, or chlorates.

In operating with two baths in two distinct ways, the textiles areplaced in baths containing either the elements of a double salt ofaniline and of metal, or the elements of a salt of aniline with ametallic acid. The textiles become dyed in this bath of a graduallydeepening green color, whether the bath be cold or heated,"and they maybe thoroughly rinsed without removing the dye. The aniline is thenperoxidized and the black developed by placing the matters to be dyed ina bath of soluble chromate, bichromate, or chlorate.

In dyeing with a single bath 1 place therein either altogether orsuccessively the whole of the constitutive elements of the black, thebath being cold when the textile materials are introduced. The reactionis allowed to com- 'mence at the ordinary temperature and the bath isthen gradually raised to about 100 centigrade. When chromates are usedthe reaction should be allowed to continue for about half an hour beforeheating; otherwise a gray shade would be produced, and the color wouldbe precipitated in the bath.

The latter method of operating in a single bath greatly facilitatesdyeing piecagoods.

The aniline salts with a metallic acid which give the best results arethose in which the metallic acid is chromicacid. With a bath containing(by reason of a double decomposition) the elements of chromate ofaniline without an excess of chromic acid, the textiles will only bedyed of a deep green, which is changed to blue-violet by means of analkali,

in exactly the same manner as with perchloride or nitrate of sesquioxideof iron. By peroxidizing with a bath of soluble bichromate or chromate,the green is changed to a black. Black may be at once produced if asuflicient quantity of the chromate or bichromate is.

placed in the bath.

When chlorate is used, the quantity of acid in the bath should besufficient to saturate the base combined with the chloric acid.

When employing chromates and bic hromates it is necessary not only tosaturate the base combined with the chromic acid, but also to saturatethe oxide of chromium resulting from the reduction of the chromic acid.

The metals whose salts are suited to one or the other of the abovereactions are those which are susceptible of two degrees of oxidation,and readily converted from the one to the other by oxidation orreduction, and the following more particularly have a very energeticaction, viz: iron, copper, manganese, cerium, chromium, nickel, cobalt,tungsten, uranium, and vanadium.

I'reserve the application of all mineral or organic acids in combinationeither with aniline or with metals, or in a free state in the dye-bath.

The quality of the color is dependent on the nature of these acids,their proportion in the bath on the metals employed, and also on thetemperature of the bath.

I will here give three examples of the method of dyeing cotton in hanks.

First example: I form ,a bath, A, containing, for one liter of water,aniline, thirty cubic centimeters; hydrochloric acid, ninety cubiccentimeters, at 22 Baum; nitrate of sesquioxide of iron, forty cubiccentimeters, at 40 Baum.

I form a second bath, B, containing from ten to twenty grams ofbichromate of potash per liter.

The cotton, in small portions at a time, is dipped in the bath A, (whichmay be either cold or tepid,) and after being slightly wrung, but notrinsed, is placed in the bath B, where it digests for about three hours.The cotton on leaving bath A retains sufficient acid to decompose theproper quantity of bichromate.

I then recommenoe the same series of operations, mordanting in bath A,and peroxidizing in bath B until the obtained shade is sufficiently laidon. Three such double passages through the baths will generally suflice.

The dyeing is complete when a sample, on being dipped in a weak warmsolution of carbonate of soda, remains of a chestnut color withoutchanging to a violet.

Second example For every ten kilograms I take of water one hundred andfifty liters; hydrochloric acid, four liters; aniline, one liter;bichromate of potash, one kilogram, five hundred grams.

Idip the cotton, after well boiling, in this bath, work it for aboutthree quarters of an hour, after which I rinse, and immerse it in aboiling bath containing one gram of persnlphate of iron, for example,per liter, slightly acidulated, for about a quarter of an hour.

Third example: I take, for one hundred kilograms of cotton, water onehundred and fifty liters; muriatic acid,"at' 22 Baum, four liters;aniline, one liter; bichromate, two kilograms, two hundred and fiftygrams.

The cotton is introduced intoa cold bath, worked for three quarters ofan hour, after which the temperature is gradually raised to 100centigrade, and kept thereat for at least one quarter of an hour.

The blacks obtained by these three methods are insoluble in coldsulphuric acid of 66 Baum, and will not turn green under the action' ofsulphurous acid. They are, in fact,

true blacks. By dilution, they give greys,

having the same properties. With a single cold bath I obtain what I termshades bor-.

dering on black or greys, these colors changing to a green under theaction of sulphurous acid.

In this manner may be dyed cotton, flax, wool, silk, feathers, and allvegetable or animal textile matters generally. For dyeing piece goodsitis preferable to use a'single bath, or at least to revive the first bathwith a salt of aniline with a metallic acid, as in the second example,before given.

The proportions of the elements indicated are those which have beenfound to give the best results, although I do not intend to limit myselfthereto.

I claim The herein-described process of dyeing vegetable or animaltextile materials of black and grey colors, or shades bordering thereon,by slow concurrent progressive reaction on the textile fibersthemselves, of aniline salts and metallic oxidizing salts or acids,without exposure to the air, and with or without heat, with a subsequentperoxidation by means of chloric or chromic acid, substantially as setforth.

WILLIAM JULES SAMUEL GRAWITZ.

Witnesses:

'RoB'r. M. HOOPER,

JEAN BAPTISTE HOLLAND.

